#[allow(unused_imports)]
use proconio::{
    input,
    marker::{Bytes, Chars, Usize1},
};
fn main() {
    input! {
        s: Chars
    }
    let mut res: Vec<char> = Vec::from([s[0]]);
    for i in 1..s.len() {
        if s[i - 1] != s[i] {
            res.push(s[i]);
        }
    }
    println!("{}", res.iter().collect::<String>());
}